diff --git a/selfdrive/car/toyota/tests/test_toyota.py b/selfdrive/car/toyota/tests/test_toyota.py
index d9d4fe087f..6a2476dff9 100755
--- a/selfdrive/car/toyota/tests/test_toyota.py
+++ b/selfdrive/car/toyota/tests/test_toyota.py
@@ -13,6 +13,10 @@ Ecu = car.CarParams.Ecu
 ECU_NAME = {v: k for k, v in Ecu.schema.enumerants.items()}
 
 
+def check_fw_version(fw_version: bytes) -> bool:
+  return b'?' not in fw_version
+
+
 class TestToyotaInterfaces(unittest.TestCase):
   def test_car_sets(self):
     self.assertTrue(len(ANGLE_CONTROL_CAR - TSS2_CAR) == 0)
@@ -59,6 +63,14 @@ class TestToyotaFingerprint(unittest.TestCase):
                          car_model in FW_QUERY_CONFIG.non_essential_ecus[Ecu.engine],
                          f"Car model unexpectedly {'not ' if len(engine_ecus) > 1 else ''}in non-essential list")
 
+  def test_valid_fw_versions(self):
+    # Asserts all FW versions are valid
+    for car_model, ecus in FW_VERSIONS.items():
+      with self.subTest(car_model=car_model.value):
+        for fws in ecus.values():
+          for fw in fws:
+            self.assertTrue(check_fw_version(fw), fw)
+
   # Tests for part numbers, platform codes, and sub-versions which Toyota will use to fuzzy
   # fingerprint in the absence of full FW matches:
   @settings(max_examples=100)